ABS moulding material with improved workability and a high lustre

ABSTRACT

A Polymer compositions that features high degree of toughness, very good processability and extremely high gloss is disclosed. The composition contains
         (I) a graft rubber polymer obtained by emulsion polymerization of styrene and acrylonitrile in the presence of a mixture of
           (A) a butadiene polymer latex having a mean particle diameter d 50 ≦250 nm, a particle size distribution width of 20 to 80 nm and a gel content of 30 to 95 wt. %,   (B) a butadiene polymer latex with a mean particle diameter d 50 &gt;250 to 350 nm, a particle size distribution width of 30 to 100 nm and gel content of 30 to 80 wt. %, and   (C) a butadiene polymer latex (C) with a mean particle diameter d 50 &gt;350 nm, a particle size distribution width of 40 to 150 nm, and a gel content of 50 to 95 wt. %. and   
           (II) a rubber-free copolymer of styrene and acrylonitrile. At least one of (A), (B) and (C) is a product of seed polymerization.

ABS moulding compositions have already been used for many years in largeamounts as thermoplastic resins for producing all types of mouldedparts. In this connection the properties of these resins may be variedwithin wide ranges.

In order to produce large-area parts, in particular housing parts, ABSpolymers are required that are characterised by a very good processingperformance, in particular by a very high thermoplastic flowability, andthat can be used to produce moulded parts having a very high surfacegloss. In this connection the other properties (e.g. toughness, modulusof elasticity) must not be negatively influenced.

Attempts have been made using emulsion polymerisation technology toproduce products having the required properties by combined use ofvarious graft rubber components in a thermoplastic resin matrix.

Thus, DE-A 24 20 357 and DE-A 24 20 358 for example describethermoplastic moulding compositions of the ABS type having hightoughness, high surface gloss and easier processability by combining acoarsely particulate graft rubber with a finely particulate graftrubber, wherein the weight ratios of styrene to acrylonitrile in thegraft rubbers and in the matrix resin must have special values.

A disadvantage of such moulding compositions of the ABS type is that twoseparately produced graft rubber polymers are required. Also, the flowproperties do not meet the requirements of modem processing technology.

EP-A 470 229, EP-A 473 400 and WO 91/13118 disclose thatimpact-resistant, high-gloss thermoplastic resins can be produced bycombining a graft polymer

having a low rubber content and small particle diameter with a graftpolymer having a high rubber content and relatively large particlediameter.

The disadvantage of these products is the not always sufficientthermoplastic flowability as well as the necessity for two separategraft polymerisation stages.

DE-A 41 13 326 describes thermoplastic moulding compositions with twodifferent graft products, wherein the rubber content of the graftrubbers are in each case at most 30 wt. %. Accordingly it is necessaryto use relatively high amounts of graft rubbers, which means that thethermoplastic flowability can be varied only within narrow ranges.Furthermore, the gloss values that can be achieved are unsatisfactoryand here too two separate graft polymerisation reactions are necessary.

Attempts have also been made by using mixtures of two rubber latices asgrafting bases to synthesise graft rubbers for the production ofimproved ABS products.

Thus for example EP-A 288 298 describes the production of products witha finely particulate and a more coarsely particulate rubber latex asgrafting bases, though only grafting rubbers with low rubber contents ofaround 40% are described. The thermoplastic resins produced therefromhave an unsatisfactory processability however on account of the poorthermoplastic flowability; furthermore resin components with highacrylonitrile contents must be used, which normally leads todiscoloration of the ABS products.

EP-A 745 624 describes the use of two rubber latices with definedparticle size distribution widths for producing ABS mouldingcompositions without any deepening of the colour shade in moulded partswith rib structures. These products however are characterised by a poorrelationship between toughness and thermoplastic processability(flowability).

The object therefore existed of providing thermoplastic mouldingcompositions of the ABS type that do not exhibit the aforementioneddisadvantages, that have a very good thermoplastic processability, andthat can be used to make moulded parts having a very high surface gloss.In this connection the ABS moulding compositions should preferablycontain a graft rubber product produced in a single process step,wherein the said graft rubber polymer should have rubber contents ofgreater than 50 wt. %, preferably above 55 wt. %.

The present invention accordingly provides polymer compositionscontaining

-   -   I) a graft rubber polymer that can be obtained by emulsion        polymerisation of styrene and acrylonitrile in a weight ratio of        95:5 to 50:50, wherein styrene and/or acrylonitrile can be        wholly or partially replaced by α-methylstyrene, methyl        methacrylate or N-phenylmaleimide or mixtures thereof, in the        presence of a mixture of a butadiene polymer latex (A) with a        mean particle diameter d₅₀≦250 nm, preferably 100 to 240 nm,        particularly preferably 130 to 230 nm and most particularly        preferably 150 to 220 nm and a particle size distribution width        (measured as d₉₀–d₁₀ from the integral particle size        distribution) of 20 to 80 nm, preferably 30 to 60 nm, and a gel        content of 30 to 95 wt. %, preferably 40 to 90 wt. % and        particularly preferably 50 to 85 wt. %, preferably obtained by        seed polymerisation using a seed latex with a mean particle        diameter d₅₀ of 10 to 100 nm, preferably 20 to 90 nm and        particularly preferably 30 to 80 nm, a butadiene polymer        latex (B) with a mean particle diameter d₅₀>250 nm to 350 nm,        preferably 260 to 340 nm and particularly preferably 270 to 320        nm, a particle size distribution width (measured as d₉₀–d₁₀ from        the integral particle size distribution) of 30 to 100 nm,        preferably 40 to 80 nm, and a gel content of 30 to 80 wt. %,        preferably 40 to 75 wt. % and particularly preferably 45 to 70        wt. %, preferably obtained by seed polymerisation using a seed        latex with a mean particle diameter d₅₀ of 30 to 150 nm,        preferably 35 to 140 nm and particularly preferably 40 to 130        nm, most particularly preferably using the same seed latex as in        the production of the polybutadiene polymer latex (A), and a        butadiene polymer latex (C) with a mean particle diameter        d₅₀>350 nm, preferably 360 to 450 nm, particularly preferably        370 to 440 nm and most particularly preferably 375 to 430 nm, a        particle size distribution width (measured as d₉₀–d₁₀ from the        integral particle size distribution) of 40 to 150 nm, preferably        50 to 100 nm, and a gel content of 50 to 95 wt. %, preferably 55        to 90 wt. % and particularly preferably 60 to 85 wt. %,        preferably obtained by seed polymerisation using a seed latex        with a mean particle diameter d₅₀ of 100 to 250 nm, preferably        120 to 240 nm and particularly preferably 150 to 220 nm, most        particularly preferably using the butadiene polymer latex (A) as        seed latex, wherein the butadiene polymer latices in each case        contain 0 to 50 wt. % of a further vinyl monomer incorporated by        copolymerisation and wherein the weight ratio of the graft        monomers that are used to the butadiene polymers that are used        is 5:95 to 70:30, preferably 10:90 to 60:40, and particularly        preferably 20:80 to 50:50, and    -   II) at least one rubber-free copolymer of styrene and        acrylonitrile in a weight ratio of 95:5 to 50:50, wherein        styrene and/or acrylonitrile can be wholly or partially replaced        by α-methylstyrene, methyl methacrylate or N-phenylmaleimide or        mixtures thereof,        wherein at least one latex selected from the butadiene polymer        latices (A), (B) and (C), preferably two latices selected from        the butadiene polymer latices (A), (B) and (C), and particularly        preferably all three butadiene polymer latices (A), (B) and (C)        is/are produced by seed polymerisation.

The butadiene polymer latices (A), (B) and (C) may in principle beemployed in arbitrary amounts in the production of the graft rubberpolymer (I).

The butadiene polymer latices (A), (B) and (C) are preferably used inthe production of the graft rubber polymer (I) in amounts of 5 to 70 wt.%, preferably 10 to 60 wt. % and particularly preferably 15 to 50 wt. %of (A), 10 to 70 wt. %, preferably 15 to 60 wt. % and particularlypreferably 20 to 55 wt. % of (B), and 5 to 60 wt. %, preferably 7.5 to50 wt. % and particularly preferably 10 to 45 wt. % of (C) (in each casereferred to the respective solids content of the latices).

In general the moulding compositions according to the invention maycontain 1 to 60 parts by weight, preferably 5 to 50 parts by weight of(I), and 40 to 99 parts by weight, preferably 50 to 95 parts by weightof (II).

The invention furthermore provides a process for producing a polymercomposition, wherein a graft rubber polymer that can be obtained byemulsion polymerisation of styrene and acrylonitrile in a weight ratioof 95:5 to 50:50, wherein styrene and/or acrylonitrile may be wholly orpartially replaced by α-methylstyrene, methyl methacrylate orN-phenyl-maleimide or mixtures thereof, is produced in the presence of amixture of a butadiene polymer latex (A) with a mean particle diameterd₅₀≦250 nm and a particle size distribution width (measured as d₉₀–d₁₀from the integral particle size distribution) of 20 to 80 nm, and a gelcontent of 30 to 95 wt. %, a butadiene polymer latex (B) with a meanparticle diameter d₅₀>250 to 350 nm, a particle size distribution width(measured as d₉₀–d₁₀ from the integral particle size distribution) of 30to 100 nm, and a gel content of 30 to 80 wt. %, and a butadiene polymerlatex (C) with a mean particle diameter d₅₀>350 nm, a particle sizedistribution width (measured as d₉₀–d₁₀ from the integral particle sizedistribution) of 40 to 150 nm, and a gel content of 50 to 95 wt. %,using at least one latex produced by seed polymerisation and selectedfrom the butadiene polymer latices (A), (B) and (C), wherein thebutadiene polymer latices in each case contain 0 to 50 wt. % of afurther vinyl monomer incorporated by copolymerisation and wherein theweight ratio of graft monomers that are used to butadiene polymers thatare used is 5:95 to 70:30, and the graft polymer is mixed with at leastone rubber-free copolymer of styrene and acrylonitrile in a weight ratioof 95:5 to 50:50, wherein styrene and/or acrylonitrile may be partiallyor wholly replaced by α-methylstyrene, methyl methacrylate orN-phenylmaleimide or mixtures thereof.

Furthermore the moulding compositions according to the invention maycontain further rubber-free thermoplastic resins that are not built upfrom vinyl monomers, wherein these thermoplastic resins are used inamounts of up to 1000 parts by weight, preferably up to 700 parts byweight and particularly preferably up to 500 parts by weight (in eachcase referred to 100 parts by weight of I+II).

The butadiene polymer latices (A), (B) and (C) may be produced byemulsion polymerisation of butadiene in a manner known per se (see forexample Houben-Weyl, Methoden der Organischen Chemie, MakromolekulareStoff, Part 1, p. 674 (1961), Thieme Verlag Stuttgart). As comonomersthere may be used up to 50 wt. % (referred to the total amount ofmonomers used in the production of the butadiene polymer) of one or moremonomers copolymerisable with butadiene.

Examples of such monomers include isoprene, chloroprene, acrylonitrile,styrene, α-methylstyrene, C₁–C₄-alkylstyrenes, C₁–C₈-alkyl acrylates,C₁–C₈-alkyl methacrylates, alkylene glycol diacrylates, alkylene glycoldimethacrylates, divinyl benzene; butadiene is preferably used alone ormixed with up to 20 wt. %, preferably with up to 10 wt. %, of styreneand/or acrylonitrile.

The polymerisation is preferably carried out according to the so-calledseed polymerisation technique, in which first of all a finely dividedpolymer, preferably a butadiene polymer, is produced as seed latex andis then further polymerised to form larger particles by further reactionwith butadiene-containing monomers.

As seed latex polymers there are preferably used butadiene polymers suchas e.g. polybutadiene, butadiene/styrene copolymers,butadiene/acrylonitrile copolymers, or polymers formed from theaforementioned monomers.

In principle other finely particulate latex polymers may also be used,for example polystyrene or styrene copolymers, poly(methyl methacrylate)or methyl methacrylate copolymers, as well as polymers of other vinylmonomers.

Preferred seed latex polymers are butadiene latices.

In this connection a seed latex with a mean particle diameter d₅₀ of 10to 100 nm, preferably 20 to 90 nm and particularly preferably 30 to 80nm is used in the production of the butadiene polymer latex (A).

In the production of the butadiene polymer latex (B) a seed latex isused with a mean particle diameter d₅₀ of 30 to 150 nm, preferably 35 to140 nm and particularly preferably 40 to 130 nm, and it is mostparticularly preferred to use the same seed latex as is used in theproduction of the butadiene polymer latex (A).

In the production of the butadiene polymer latex (C) a seed latex isused with a mean particle diameter d₅₀ of 100 to 250 nm, preferably 120to 240 nm and particularly preferably 150 to 220 nm, and it is mostparticularly preferred to use the butadiene polymer latex (A) as seedlatex.

The seed latex polymers have a gel content of 10 to 95 wt. %, preferably20 to 90 wt. % and particularly preferably 30 to 85 wt. %.

The butadiene polymer latex (A) has a mean particle diameter d₅₀≦250 nm,preferably 100 to 240 nm, particularly preferably 130 to 230 nm, andmost particularly preferably 150 to 220 nm, a particle size distributionwidth (measured as d₅₀−d₁₀ from the integral particle size distribution)of 20 to 80 nm, preferably 30 to 60 nm, and a gel content of 30 to 95wt. %, preferably 40 to 90 wt. %, and particularly preferably 50 to 85wt. %

The butadiene polymer latex (B) has a mean particle diameter d₅₀ of >250nm to 350 nm, preferably 260 to 340 nm and particularly preferably 270to 320 nm, a particle size distribution width (measured as d₅₀−d₁₀ fromthe integral particle size distribution) of 30 to 100 nm, preferably 40to 80 nm, and a gel content of 30 to 80 wt. %, preferably 40 to 75 wt.%, and particularly preferably 45 to 70 wt. %.

The butadiene polymer latex (C) has a mean particle diameter d₅₀ of >350nm, preferably 360 to 450 nm, particularly preferably 370 to 440 nm, andmost particularly preferably 375 to 430 nm, a particle size distributionwidth (measured as d₅₀−d₁₀ from the integral particle size distribution)of 40 to 150 nm, preferably 50 to 100 nm, and a gel content of 50 to 95wt. %, preferably 55 to 90 wt. %, and particularly preferably 60 to 85wt. %.

The mean particle diameter d₅₀, as well as the d₁₀ values and d₉₀values, can be determined by ultracentrifugation measurements (see W.Scholtan, H. Lange: Kolloid Z. u. Z. Polymere 250, pp. 782 to 796(1972)), the specified values for the gel content referring to thedetermination by the wire cage method in toluene (see Houben-Weyl,Methoden der Organischen Chemie, Makromolkulare Stoffe, Part I, p. 307(1961), Thieme Verlag Stuttgart).

The gel contents of the butadiene polymer latices (A), (B) and (C) aswell as of the seed polymer latices may in principle be adjusted in amanner known per se by employing suitable reaction conditions (e.g. highreaction temperature and/or polymerisation up to a high degree ofconversion as well as optionally the addition of crosslinking substancesin order to achieve a high gel content, or for example a low reactiontemperature and/or termination of the polymerisation reaction before toohigh a degree of crosslinking has occurred, as well as optionally theaddition of molecular weight regulators such as n-dodecyl mercaptan ort-dodecyl mercaptan in order to achieve a low gel content). Asemulsifiers there may be used conventional anionic emulsifiers such asalkyl sulfates, alkyl sulfonates, aralkyl sulfonates, soaps of saturatedor unsaturated fatty acids, as well as alkaline disproportionated orhydrogenated abietinic acid or tall oil acid, and preferably emulsifiershaving carboxyl groups are used (e.g. salts of C₁₀–C₁₈ fatty acids,disproportionated abietinic acid, emulsifiers according to DE-OS 36 39904 and DE-OS 39 13 509).

In order to achieve the effect according to the invention at least onelatex selected from the butadiene polymer latex components (A), (B) and(C), preferably two latices selected from the butadiene polymer latexcomponents (A), (B) and (C), and particularly all three butadienepolymer latex components (A), (B) and (C) must have been produced byseed polymerisation.

The graft polymerisation in the production of the graft polymer I) maybe carried out according to any suitable methods, but is preferablycarried out in such a way that the monomer mixture is continuously addedto the mixture of the butadiene polymer latices (A), (B) and (C), and ispolymerised.

Special monomer/rubber ratios are preferably maintained during thepolymerisation, and the monomers are added to the rubber in a mannerknown per se.

In order to produce the component I) according to the invention,preferably 15 to 50 parts by weight, particularly preferably 20 to 40parts by weight, of a mixture of styrene and acrylonitrile that mayoptionally contain up to 50 wt. % (referred to the total amount of themonomers employed in the graft polymerisation) of one or morecomonomers, are polymerised in the presence of preferably 50 to 85 partsby weight, particularly preferably 60 to 80 parts by weight (in eachcase referred to solids) of the butadiene polymer latex mixture of (A),(B) and (C).

The monomers used in the graft polymerisation are preferably mixtures ofstyrene and acrylonitrile in a weight ratio of 95:5 to 50:50,particularly preferably in a weight ratio of 80:20 to 65:35, whereinstyrene and/or acrylonitrile may be wholly or partially replaced bycopolymerisable monomers, preferably by α-methylstyrene, methylmethacrylate or N-phenylmaleimide. In principle arbitrary furthercopolymerisable vinyl monomers may additionally be used in amounts of upto ca. 10 wt. % (referred to the total amount of the monomers).

In addition molecular weight regulators may be used in the graftpolymerisation, preferably in amounts of 0.01 to 2 wt. %, particularlypreferably in amounts of 0.05 to 1 wt. % (in each case referred to thetotal amount of monomers in the graft polymerisation stage).

Suitable molecular weight regulators are for example alkyl mercaptanssuch as n-dodecyl mercaptan, t-dodecyl mercaptan; dimericα-methylstyrene; terpinolene.

Suitable initiators that may be used include inorganic and organicperoxide, e.g. H₂O₂, di-tert.-butyl peroxide, cumene hydroperoxide,dicyclohexyl percarbonate, tert.-butyl hydroperoxide, p-menthanehydroperoxide, azo initiators such as azobisisobutyronitrile, persaltssuch as ammonium, sodium or potassium persulfate, potassiumperphosphate, sodium perborate, as well as redox systems. Redox systemsconsist as a rule of an organic oxidising agent and a reducing agent, inwhich connection heavy metal ions may in addition be present in thereaction medium (see Houben-Weyl, Methoden der Organischen Chemie, Vol.14/1, pp. 263 to 297).

The polymerisation temperature is in general 25° C. to 160° C.,preferably 40° C. to 90° C. Suitable emulsifiers are mentioned above.

The polymerisation may be carried out under normal temperatureconditions, i.e. isothermally; the graft polymerisation is howeverpreferably carried out so that the temperature difference between thestart and end of the reaction is at least 10° C., preferably at least15° C., and particularly preferably at least 20° C.

In order to produce the component I) according to the invention, thegraft polymerisation may preferably be carried out by addition of themonomers in such a way that 55 to 90 wt. %, preferably 60 to 80 wt. %and particularly preferably 65 to 75 wt. % of the total amount ofmonomers used in the graft polymerisation are metered in during thefirst half of the overall time for metering in the monomers; theremaining proportion of the monomers is metered in within the secondhalf of the overall time for metering in the monomers.

As rubber-free copolymers II) there are preferably used copolymers ofstyrene and acrylonitrile in a weight ratio of 95:5 to 50:50, in whichconnection styrene and/or acrylonitrile may be wholly or partiallyreplaced by α-methylstyrene, methyl methacrylate or N-phenylmaleimide.

Particularly preferred are copolymers II) containing proportions ofincorporated acrylonitrile units of ≦30 wt. %.

These copolymers preferably have mean molecular weights {overscore(M)}_(w) of 20,000 to 200,000 and intrinsic viscosities [η] of 20 to 110ml/g (measured in dimethylformamide at 25° C.).

Details regarding the production of these resins are described forexample in DE-A 2 420 358 and DE-A 2 724 360. Vinyl resins produced bybulk polymerisation or solution polymerisation have proved to beparticularly suitable. The copolymers may be added alone or as anarbitrary mixture.

Apart from using thermoplastic resins built up from vinyl monomers, itis also possible to use polycondensates, for example aromaticpolycarbonates, aromatic polyester carbonates, polyesters or polyamidesas rubber-free copolymer in the moulding compositions according to theinvention.

Suitable thermoplastic polycarbonates and polyester carbonates are known(see for example DE-A 1 495 626, DE-A 2 232 877, DE-A 2 703 376, DE-A 2714 544, DE-A 3 000 610, DE-A 3 832 396, DE-A 3 077 934), which may beprepared for example by reacting diphenols of the formulae (III) and(IV)

in which

-   -   A denotes a single bond C₁–C₅-alkylene, C₂–C₅-alkylidene,        C₅–C₆-cycloalkylidene, —O—, —S—, —SO—, —SO₂— or —CO—,    -   R⁵ and R⁶ independently of one another denote hydrogen, methyl        or halogen, in particular hydrogen, methyl, chlorine or bromine,    -   R¹ and R² independently of one another denote hydrogen, halogen,        preferably chlorine or bromine, C₁–C₈-alkyl, preferably methyl,        ethyl, C₅–C₆-cycloalkyl, preferably cyclohexyl, C₆–C₁₀-aryl,        preferably phenyl, or C₇–C₁₂-aralkyl, preferably phenyl        —C₁–C₄-alkyl, in particular benzyl,    -   m is an integer from 4 to 7, preferably 4 or 5,    -   n is 0 or 1,    -   R³ and R⁴ may be selected individually for each X and        independently of one another denote hydrogen or C₁–C₆-alkyl, and    -   X denotes carbon,        with carbonic acid halides, preferably phosgene, and/or with        aromatic dicarboxylic acid dihalides, preferably        benzenedicarboxylic acid dihalides, by phase boundary        polycondensation, or with phosgene by polycondensation in the        homogeneous phase (so-called pyridine process), in which        connection the molecular weight may be adjusted in a manner        known per se by adding an appropriate amount of known chain        terminators.

Suitable diphenols of the formulae (III) and (IV) are for examplehydroquinone, resorcinol, 4,4′-dihydroxydiphenyl,2,2-bis-(4-hydroxyphenyl)-propane,2,4-bis-(4-hydroxyphenyl)-2-methylbutane,2,2-bis-(4-hydroxy-3,5-dimethylphenyl)-propane,2,2-bis-(4-hydroxy-3,5-dichlorophenyl)-propane,2,2-bis-(4-hydroxy-3,5-dibromophenyl)-propane,1,1-bis-(4-hydroxyphenyl)-cyclohexane,1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane,1,1-bis-(4-hydroxyphenyl)-3,3-dimethylcyclohexane,1,1-bis-(4-hydroxyphenyl)-3,3,5,5-tetramethylcyclohexane or1,1-bis-(4-hydroxyphenyl)-2,4,4,-trimethylcyclopentane.

Preferred diphenols of the formula (III) are2,2-bis-(4-hyroxyphenyl)-propane and1,1-bis-(4-hydroxyphenyl)-cyclohexane, and the preferred phenol of theformula (IV) is 1,1-bis-(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.

Mixtures of diphenols may also be used.

Suitable chain terminators are for example phenol, p-tert.-butylphenol,long-chain alkyl phenols such as 4-(1,3-tetramethylbutyl)phenolaccording to DE-A 2 842 005, monoalkylphenols, dialkylphenols having atotal of 8 to 20 C atoms in the alkyl substituents according to DE-A 3506 472, such as p-nonylphenol, 2,5-di-tert.-butylphenol,p-tert.-octylphenol, p-dodecylphenol, 2-(3,5-dimethylheptyl)-phenol and4-(3,5-dimethylheptyl)-phenol. The necessary amount of chain terminatorsis generally 0.5 to 10 mole % referred to the sum of the diphenols (II)and (IV).

The suitable polycarbonates or polyester carbonates may be linear orbranched; branched products are preferably obtained by incorporating0.05 to 2.0 mole %, referred to the sum of the diphenols employed, oftrifunctional or higher functionality compounds, for example thosehaving three or more than three phenolic OH groups.

The suitable polycarbonates or polyester carbonates may containaromatically bound halogen, preferably bromine and/or chlorine; however,they are preferably halogen-free.

The polycarbonates and polyester carbonates have mean molecular weights({overscore (M)}_(w), weight average), determined for example byultracentrifugation or light scattering measurements, of 10,000 to200,000, preferably 20,000 to 80,000.

Suitable thermoplastic polyesters are preferably polyalkyleneterephthalates, i.e. reaction products of aromatic dicarboxylic acids ortheir reactive derivatives (e.g. dimethyl esters or anhydrides) withaliphatic, cycloaliphatic or arylaliphatic diols and mixtures of suchreaction products.

Preferred polyalkylene terephthalates can be prepared from terephthalicacids (or their reactive derivatives) and aliphatic or cycloaliphaticdiols with 2 to 10 C atoms according to known methods(Kunststoff-Handbuch, Vol. VIII, p. 695 ff, Carl Hanser Verlag, Munich1973).

In preferred polyalkylene terephthalates 80 to 100 mole %, preferably 90to 100 mole % of the dicarboxylic acid residues are terephthalic acidresidues, and 80 to 100 mole %, preferably 90 to 100 mole % of the diolresidues are ethylene glycol residues and/or butanediol-1,4 residues.

The preferred polyalkylene terephthalates may in addition to ethyleneglycol residues or butanediol-1,4 residues also contain 0 to 20 mole %of residues of other aliphatic diols with 3 to 12 C atoms orcycloaliphatic diols with 6 to 12 C atoms, for example residues ofpropanediol-1,3, 2-ethylpropanediol-1,3, neopentyl glycol,pentanediol-1,5, hexanediol-1,6, cyclohexanedimethanol-1,4,3-methylpentanediol-1,3 and -1,6, 2-ethylhexanediol-1,3,2,2-diethylpropanediol-1,3, hexanediol-2,5,1,4-di(β-hydroxyethoxy)-benzene, 2,2-bis-4-(hydroxycyclohexyl)-propane,2,4-dihydroxy-1,1,3,3-tetramethylcyclobutane,2,2-bis-(3-β-hydroxyethoxyphenyl)-propane and2,2-bis-(4-hydroxypropoxyphenyl)-propane (DE-OS 2 407 647, 2 407 776, 2715 932).

The polyalkylene terephthalates may be branched by incorporatingrelatively small amounts of trihydroxy or tetrahydroxy alcohols or3-basic or 4-basic carboxylic acids, such as as are described in DE-OS 1900 270 and in U.S. Pat. No. 3,692,744. Examples of preferred branchingagents are trimesic acid, trimellitic acid, trimethylolethane andtrimethylolpropane, and pentacrythritol. It is advisable to use not morethan 1 mole % of the branching agent, referred to the active component.

Particularly preferred are polyalkylene terephthalates that have beenproduced solely from terephthalic acid and its reactive derivatives (forexample its dialkyl esters) and ethylene glycol and/or butanediol-1,4,and mixtures of these polyalkylene terephthalates.

Preferred polyalkylene terephthalates are also copolyesters that havebeen prepared from at least two of the abovementioned alcoholcomponents: particularly preferred copolyesters arepoly-(ethyleneglycolbutanediol-1,4)-terephthalates.

The preferably suitable polyalkylene terephthalates generally have anintrinsic viscosity of 0.4 to 1.5 dl/g, preferably 0.5 to 1.3 dl/g, inparticular 0.6 to 1.2 dl/g, measured in each case inphenol/o-dichlorobenzene (1:1 parts by weight) at 25° C.

Suitable polyamides are known homopolyamides, copolyamides and mixturesof these polyamides. These polyamides may be partially crystallineand/or amorphous.

Suitable partially crystalline polyamides are polyamide-6,polyamide-6,6, mixtures and corresponding copolymers prepared from thesecomponents. Also suitable are partially crystalline polyamides whoseacid component consists wholly or partially of terephthalic acid and/orisophthalic acid and/or cork acid and/or sebacic acid and/or azelaicacid and/or adipic acid and/or cyclohexanedicarboxylic acid, whosediamine component consists wholly or partially of m- and/or p-xylylenediamine and/or hexamethylene diamine and/or 2,2,4-trimethylhexamethylenediamine and/or 2,2,4-trimethylhexamethylene diamine and/or isophoronediamine, and whose composition is in principle known.

There may also be mentioned polyamides that have been produced wholly orpartially from lactams with 7 to 12 C atoms in the ring, optionally withthe co-use of one or more of the abovementioned starting components.

Particularly preferred partially crystalline polyamides are polyamide-6and polyamide 6,6 and their mixtures. As amorphous polyamides there maybe used known products that are obtained by polycondensation of diaminessuch as ethylene diamine, hexamethylene diamine, decamethylene diamine,2,2,4- and/or 2,4,4-trimethylhexamethylene diamine, m- and/or p-xylylenediamine, bis-(4-aminocyclohexyl)-methane,bis-(4-aminocyclohexyl)-propane,3,3′-dimethyl-4,4′-diamino-dicyclohexylmethane,3-aminomethyl-3,5,5,-trimethylcyclohexylamine, 2,5- and/or2,6-bis-(aminomethyl)-norbornane and/or 1,4-diaminomethylcyclohexanewith dicarboxylic acids such as oxalic acid, adipic acid, azelaic acid,decanedicarboxylic acid, heptadecanedicarboxylic acid, 2,2,4- and/or2,4,4-trimethyladipic acid, isophthalic acid and terephthalic acid.

Also suitable are copolymers obtained by polycondensation of severalmonomers, as well as copolymers prepared with the addition ofaminocarboxylic acids such as ε-aminocaproic acid, ω-aminoundecanoicacid or ω-aminolauric acid or their lactams.

Particularly suitable amorphous polyamides are the polyamides preparedfrom isophthalic acid, hexamethylene diamine and further diamines suchas 4,4′-diaminodicyclohexylmethane, isophorone diamine, 2,2,4- and/or2,4,4-trimethylhexamethylene diamine, 2,5- and/or2,6-bis-(aminomethyl)-nobornene; or from isophthalic acid,4,4′-diaminodicyclohexylmethane and ε-caprolactam; or from isophthalicacid, 3,3′-dimethyl-4,4′-diaminodicyclohexylmethane and laurinlactam; orfrom terephthalic acid and the isomeric mixture of 2,2,4- and/or2,4,4-trimethylhexamethylene diamine.

Instead of the pure 4,4′-diaminodicyclohexylmethane, mixtures of thepositional isomeric diaminodicyclohexylmethanes consisting of thefollowing components may also be used

-   -   70 to 99 mole % of the 4,4′-diamino isomer    -   1 to 30 mole % of the 2,4′-diamino isomer    -   0 to 2 mole % of the 2,2′-diamino isomer, and        optionally correspondingly higher condensed diamines that are        obtained by hydrogenating industrial quality        diaminodiphenylmethane. The isophthalic acid may be replaced in        an amount of up to 30% by terephthalic acid.

The polyamides preferably have a relative viscosity (measured in a 1 wt.% solution in m-cresol at 25° C.) of 2.0 to 5.0, particularly preferably2.5 to 4.0.

Preferred moulding compositions according to the invention contain 1 to60 parts by weight, preferably 5 to 50 parts by weight of graft polymercomponent I) and 40 to 99 parts by weight, preferably 50 to 95 parts byweight of rubber-free copolymer II).

The production of the moulding compositions according to the inventionis carried out by mixing the components I) and II) in conventionalmixing units (preferably in multiple roll mills, mixing extruders orinternal kneaders).

The invention furthermore provides a process for producing the mouldingcompositions according to the invention, wherein the components I) andII) are mixed and are compounded and extruded at elevated temperature,in general at temperatures from 150° C. to 300° C.

Necessary and/or advantageous additives, for example antioxidants, UVstabilisers, peroxide destroyers, antistatic agents, lubricating agents,mould release agents, flame protection agents, fillers or reinforcingmaterials (glass fibres, carbon fibres etc.) and, pigments may be addedto the moulding compositions according to the invention during theproduction, processing, further processing and final shaping stages.

The final shaping may be carried out in conventional processing units,and includes for example processing by injection moulding, sheetextrusion optionally followed by heat forming, cold forming, extrusionof pipes and profiled sections, and calender processing.

In the following examples the specified parts are always parts by weightand the specified % are always wt. % unless otherwise stated.

EXAMPLES

Components

ABS Graft Polymer 1 (according to the invention)

15 parts by weight (calculated as solids) of an anionically emulsifiedpolybutadiene latex with a mean particle diameter d₅₀ of 191 nm, aparticle size distribution width d₉₀–d₁₀ of 42 nm and a gel content of69 wt. % produced by free-radical seed polymerisation using apolybutadiene latex with a d₅₀ value of 46 nm, 30 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 297 nm, a particle sizedistribution width d₉₀–d₁₀ of 77 nm and a gel content of 61 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 125 nm as seed latex, and 15 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 422 nm, a particle sizedistribution width d₉₀–d₁₀ of 63 nm and a gel content of 80 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 125 nm as seed latex are adjusted with water to asolids content of ca. 20 wt. %, heated to 59° C., following which 0.5part by weight of potassium peroxodisulfate (dissolved in water) isadded.

40 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. % ofacrylonitrile and 0.12 parts by weight of tert.-dodecyl mercaptan areuniformly metered in within 6 hours, and in parallel to this 1 part byweight (calculated as solids) of the sodium salt of a resin acid mixture(Dresinate 731, Abieta Chemie GmbH, Gersthofen, Germany, dissolved inalkaline adjusted water) is metered in over a period of 6 hours. Duringthe course of the 6 hours the reaction temperature is raised from 59° C.to 77° C. After a post-reaction time of 2 hours at 80° C. the graftlatex is coagulated after adding ca. 1.0 part by weight of a phenolicantioxidant, with a magnesium sulfate/acetic acid mixture and, afterwashing with water, the resulting moist powder is dried at 70° C.

ABS Graft Polymer 2 (according to the invention)

15 parts by weight (calculated as solids) of an anionically emulsifiedpolybutadiene latex with a mean particle diameter d₅₀ of 189 nm, aparticle size distribution width d₉₀–d₁₀ of 50 nm and a gel content of76 wt. % produced by free-radical seed polymerisation using apolybutadiene latex with a d₅₀ of 46 nm as seed latex, 30 parts byweight (calculated as solids) of an anionically emulsified polybutadienelatex with a mean particle diameter d₅₀ of 285 nm, a particle sizedistribution width d₉₀–d₁₀ of 60 nm and a gel content of 67 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 119 nm as seed latex, and 15 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 399 nm, a particle sizedistribution width d₉₀–d₁₀ of 56 nm and a gel content of 85 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 189 nm as seed latex are adjusted with water to asolids content of ca. 20 wt. %, heated to 55° C., following which 0.5part by weight of potassium peroxodisulfate (dissolved in water) isadded.

40 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. % ofacrylonitrile and 0.12 part by weight of tert.-dodecyl mercaptan areuniformly metered in within 5 hours, and in parallel to this 1 part byweight (calculated as solids) of the sodium salt of a resin acid mixture(Dresinate 731, Abieta Chemie GmbH, Gersthofen, Germany, dissolved inalkaline adjusted water) is metered in over a period of 5 hours. Duringthe course of the 5 hours the reaction temperature is raised from 55° C.to 80° C. After a post-reaction time of 2 hours at 80° C. the graftlatex is coagulated after adding ca. 1.0 part by weight of a phenolicantioxidant, with a magnesium sulfate/acetic acid mixture, and afterwashing with water the resulting moist powder is dried at 70° C.

ABS Graft Polymer 3 (according to the invention)

15 parts by weight (calculated as solids) of an anionically emulsifiedpolybutadiene latex with a mean particle diameter d₅₀ of 185 nm, aparticle size distribution width d₉₀–d₁₀ of 51 nm and a gel content of69 wt. % produced by free-radical seed polymerisation using apolybutadiene seed latex with a d₅₀ of 48 nm, 30 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 297 nm, a particle sizedistribution width d₉₀–d₁₀ of 77 nm and a gel content of 61 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 125 nm as seed latex, and 15 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 422 nm, a particle sizedistribution width d₉₀–d₁₀ of 63 nm and a gel content of 80 wt. %produced by free-radical seed polymerisation using a polybutadiene seedlatex with a d₅₀ value of 185 nm, are adjusted with water to a solidscontent of ca. 20 wt. %, heated to 55° C., following which 0.5 part byweight of potassium peroxodisulfate (dissolved in water) is added.

40 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. % ofacrylonitrile and 0.12 parts by weight of tert.-dodecyl mercaptan areuniformly metered in within 5 hours, and in parallel to this 1 part byweight (calculated as solids) of the sodium salt of a resin acid mixture(Dresinate 731, dissolved in alkaline adjusted water) is metered in overa period of 5 hours. During the course of the 5 hours the reactiontemperature is raised from 55° C. to 80° C. After a post-reaction timeof 2 hours at 80° C. the graft latex is coagulated after adding ca. 1.0part by weight of a phenolic antioxidant, with a magnesiumsulfate/acetic acid mixture, and after washing with water the resultingmoist powder is dried at 70° C.

ABS Graft Polymer 4 (according to the invention)

20 parts by weight (calculated as solids) of an anionically emulsifiedpolybutadiene latex with a mean particle diameter d₅₀ of 185 nm, aparticle size distribution width d₉₀–d₁₀ of 51 nm and a gel content of69 wt. % produced by free-radical seed polymerisation using apolybutadiene seed latex with a d₅₀ of 48 nm, 27.5 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 297 nm, a particle sizedistribution width d₉₀–d₁₀ of 77 nm and a gel content of 61 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 125 nm as seed latex, and 12.5 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 422 nm, a particle sizedistribution width d₉₀−d₁₀ of 63 nm and a gel content of 80 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 185 nm as seed latex, are adjusted with water to asolids content of ca. 20 wt. %, heated to 55° C., following which 0.5part by weight of potassium peroxodisulfate (dissolved in water) isadded.

40 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. % ofacrylonitrile and 0.12 parts by weight of tert.-dodecyl mercaptan areuniformly metered in within 5 hours, and in parallel to this 1 part byweight (calculated as solids) of the sodium salt of a resin acid mixture(Dresinate 731, dissolved in alkaline adjusted water) is metered in overa period of 5 hours. During the course of the 5 hours the reactiontemperature is raised from 55° C. to 80° C. After a post-reaction timeof 2 hours at 80° C. the graft latex is coagulated after adding ca. 1.0part by weight of a phenolic antioxidant, with a magnesiumsulfate/acetic acid mixture, and after washing with water the resultingmoist powder is dried at 70° C.

ABS Graft Polymer 5 (according to the invention)

17.5 parts by weight (calculated as solids) of an anionically emulsifiedpolybutadiene latex with a mean particle diameter d₅₀ of 189 nm, aparticle size distribution width d₉₀–d₁₀ of 50 nm and a gel content of76 wt. % produced by free-radical seed polymerisation using apolybutadiene seed latex with a d₅₀ of 46 nm, 35 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 285 nm, a particle sizedistribution width d₉₀–d₁₀ of 60 nm and a gel content of 67 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 119 nm as seed latex, and 17.5 parts by weight(calculated as solids) of an anionically emulsified polybutadiene latexwith a mean particle diameter d₅₀ of 399 nm, a particle sizedistribution width d₉₀–d₁₀ of 56 nm and a gel content of 85 wt. %produced by free-radical seed polymerisation using a polybutadiene latexwith a d₅₀ value of 189 nm as seed latex, are adjusted with water to asolids content of ca. 20 wt. %, heated to 55° C., following which 0.5part by weight of potassium peroxodisulfate (dissolved in water) isadded.

30 parts by weight of a mixture of 73 wt. % of styrene, 27 wt. % ofacrylonitrile and 0.1 part by weight of tert.-dodecyl mercaptan are thenuniformly added within 6 hours. The further production is carried out asdescribed in ABS graft polymer 1.

ABS Graft Polymer 6 (according to the invention)

15 parts by weight (calculated as solids) of an anionically emulsifiedbutadiene/styrene (90:10) copolymer latex with a mean particle diameterd₅₀ of 176 nm, a particle size distribution width d₉₀–d₁₀ of 48 nm and agel content of 60 wt. %, produced by free-radical seed polymerisationusing a butadiene/styrene (90:10) copolymer latex with a d₅₀ value of 39nm as seed latex, 30 parts by weight (calculated as solids) of ananionically emulsified polybutadiene with a mean particle diameter d₅₀of 285 nm, a particle size distribution width d₉₀–d₁₀ of 60 nm and a gelcontent of 67 wt. % produced by free-radical seed polymerisation using apolybutadiene latex with a d₅₀ value of 119 nm as seed latex, and 15parts by weight (calculated as solids) of an anionically emulsifiedbutadiene/styrene (90:10) copolymer latex with a mean particle diameterd₅₀ of 391 nm, a particle size distribution width d₉₀–d₁₀ of 75 nm and agel content of 74 wt. % produced by free-radical seed polymerisationusing a butadiene/styrene (90:10) copolymer latex with a d₅₀ value of176 nm as seed latex, are adjusted with water to a solids content of ca.20 wt. %, heated to 55° C., followed which 0.5 part by weight ofpotassium peroxodisulfate (dissolved in water) is added.

40 parts by weight of a mixture of 73 wt. % of styrene and 27 wt. % ofacrylonitrile are then uniformly metered in within 5 hours, 0.12 part byweight of tert.-dodecyl mercaptan being uniformly metered in within thefirst 4 hours. In parallel to this 1 part by weight (calculated assolids) of the sodium salt of a resin acid mixture (Dresinate 731,Abieta Chemie GmbH, Gersthofen, Germany, dissolved in alkaline adjustedwater) is metered in over a period of 5 hours. During the course of the5 hours the reaction temperature is raised from 55° C. to 80° C. Thefurther production is carried out as described in the ABS graft polymer1.

ABS Graft Polymer 7 (comparison material, not according to theinvention)

The production described under “ABS graft polymer 1” is repeated,wherein a polybutadiene latex with a mean particle diameter d₅₀ of 183nm, a particle size distribution width d₉₀–d₁₀ of 103 nm and a gelcontent of 79 wt. %, produced without using seed latex was used asfinely particulate rubber component, a polybutadiene latex with a meanparticle diameter d₅₀ of 305 nm, a particle size distribution widthd₉₀–d₁₀ of 108 nm and a gel content of 55 wt. % was used as meanparticulate rubber component, and a polybutadiene latex with a meanparticle diameter d₅₀ of 423 nm, a particle size distribution widthd₉₀–d₁₀ of 99 nm and a gel content of 78 wt. % produced without usingseed latex was used as coarsely particulate rubber component.

ABS graft polymer 8 (comparison material, not according to theinvention)

The production described under “ABS graft polymer 1” is repeated,wherein instead of the polybutadiene latex mixture there were used 60parts by weight (calculated as solids) of a polybutadiene latex with amean particle diameter d₅₀ of 131 nm, a particle size distribution widthd₉₀–d₁₀ of 76 nm and a gel content of 88 wt. % produced without usingseed latex.

ABS graft polymer 9 (comparison material, not according to theinvention)

The production described under “ABS graft polymer 1” is repeated, exceptthat instead of the polybutadiene latex mixture there were used 60 partsby weight (calculated as solids) of a polybutadiene latex with a meanparticle diameter d₅₀ of 423 nm, a particle size distribution widthd₉₀–d₁₀ of 99 nm and a gel content of 78 wt. % produced without usingseed latex.

Resin Component 1

Statistical styrene/acrylonitrile copolymer (styrene/acrylonitrileweight ratio 72:28) with a {overscore (M)}_(w) of ca. 85,000 and{overscore (M)}_(w)/{overscore (M)}_(n)−1≦2 obtained by free-radicalsolution polymerisation.

Resin Component 2

Statistical styrene/acrylonitrile copolymer (styrene:acrylonitrileweight ratio 72:28) with a {overscore (M)}_(w) of ca. 115,000 and{overscore (M)}_(w)/{overscore (M)}_(n)1≦2 obtained by free-radicalsolution polymerisation.

Moulding Compositions

The aforedescribed polymer components are mixed in the proportions givenin Table 1 together with 2 parts by weight of ethylenediamine bisstearylamide and 0.1 part by weight of a silicone oil in an internal kneader,and after granulation are processed into test pieces and into a flatsheet (in order to evaluate the surface).

The following data are obtained:

notched impact strength at room temperature (a_(k)) according to ISO180/1A (unit: kJ/m²), thermoplastic flowability (MVI) according to DIN53735U (unit: cm³/10 min) and surface gloss according to DIN 67530 at areflecting angle of 20° (reflectometer value).

It is clear from the Examples (test data see Table 2) that the mouldingcompositions according to the invention are characterised by acombination of high toughness values, very good processability andextremely high gloss values.

TABLE 1 Compositions of the moulding compositions ABS ABS ABS ABS ABSABS ABS ABS ABS Graft Graft Graft Graft Graft Graft Graft Graft GraftResin Resin Polymer Polymer Polymer Polymer Polymer Polymer PolymerPolymer Polymer Component Component 1 2 3 4 5 6 7 8 9 1 2 (parts (parts(parts (parts (parts (parts (parts (parts (parts (parts (parts Exampleby wt.) by wt.) by wt.) by wt.) by wt.) by wt.) by wt.) by wt.) by wt.)by wt.) by wt.)  1 27 — — — — — — — — 73 —  2 — 27 — — — — — — — 73 —  3— — 27 — — — — — — 73 —  4 — — — 27 — — — — — 73 —  5 — — — — 23.2 — — —— 76.8 —  6 — — — — — 27 — — — 73 —  7(Comparison) — — — — — — 27 — — 73—  8(Comparison) — — — — — — — 13.5 13.5 73 —  9 40 — — — — — — — — — 6010 — — 40 — — — — — — — 60 11(Comparison) — — — — — — — — 40   — 60

TABLE 2 Test data of the moulding compositions Example a_(k) (kJ/m²) MVI(cm³/10 min) Degree of Gloss  1 18.1 39.9 98  2 19.2 39.0 96  3 19.439.1 96  4 17.1 40.2 96  5 19.4 38.3 95  6 18.6 40.1 96  7 (Comparison)19.1 36.2 92  8 (Comparison) 18.3 35.2 93  9 32.0 8.1 95 10 30.8 8.5 9511 (Comparison) 30.3 7.6 88

1. Polymer compositions containing I) a graft rubber polymer that isobtained by emulsion polymerisation of styrene and acrylonitrile in aweight ratio of 95:5 to 50:50, wherein styrene and/or acrylonitrile canbe wholly or partially replaced by α-methyistyrene, methyl methacrylateor N-phenylmaleimide or mixtures thereof, in the presence of a mixtureof a butadiene polymer latex (A) with a mean particle diameter d₅₀≦250nm and a particle size distribution width (measured as d₉₀–d₁₀ from theintegral particle size distribution) of 20 to 80 nm and a gel content of30 to 95 wt. %, a butadiene polymer latex (B) with a mean particlediameter d₅₀>250 to 350 nm, a particle size distribution width (measuredas d₉₀–d₁₀ from the integral particle size distribution) of 30 to 100 nmand a gel content of 30 to 80 wt. %, and a butadiene polymer latex (C)with a mean particle diameter d₅₀>350 nm, a particle size distributionwidth (measured as d₉₀–d₁₀ from the integral particle size distribution)of 40 to 150 nm, and a gel content of 50 to 95 wt %, wherein thebutadiene polymer latices in each case contain 0 to 50 wt. % of afurther vinyl monomer incorporated by copolymerisation and wherein themass ratio of the graft monomers that are used to the butadiene polymersthat are used is 5:95 to 70:30, and II) at least one rubber-freecopolymer of styrene and acrylonitrile in a weight ratio of 95:5 to50:50, wherein styrene and/or acrylonitrile can be wholly or partiallyreplaced by α-methylstyrene, methyl methacrylate or N-phenylmaleimide ormixtures thereof, wherein at least one latex selected from the butadienepolymer latices (A), (B) and (C) is produced by seed polymerisation. 2.Polymer compositions according to claim 1, wherein the butadiene polymerlatex (A) has a mean particle diameter d₅₀ of 100 to 240 nm, a particlesize distribution width (measured as d₉₀>d₁₀ from the integral particlesize distribution) of 30 to 60 nm and a gel content of 40 to 90 wt. %,the butadiene polymer latex (B) has a mean particle diameter d₅₀ of 260to 340 nm, a particle size distribution width (measured as d₉₀–d₁₀ fromthe integral particle size distribution) of 40 to 80 nm, and a gelcontent of 40 to 75 wt. %, and the butadiene polymer latex (C) has amean particle diameter d₅₀ of 360 to 450 nm, a particle sizedistribution width (measured as d₉₀–d₁₀ from the integral particle sizedistribution) of 50 to 100 nm and a gel content of 55 to 90 wt. %. 3.Polymer compositions according to claim 1 wherein the butadiene polymerlatex (A) has a mean particle diameter d₅₀ of 130 to 230 nm and aparticle size distribution width (measured as d₉₀–d₁₀ from the integralparticle size distribution) of 30 to 60 nm and a gel content of 50 to 85wt. %, the butadiene polymer latex (B) has a mean particle diameter d₅₀of 270 to 320 nm, a particle size distribution width (measured asd₉₀–d₁₀ from the integral particle size distribution) of 40 to 80 nm,and a gel content of 45 to 70 wt. %, and the butadiene polymer latex (C)has a mean particle diameter d₅₀ of 375 to 430 nm, a particle sizedistribution width (measured as d₉₀–d₁₀ from the integral particle sizedistribution) of 50 to 100 nm and a gel content of 60 to 85 wt %. 4.Polymer composition according to claim 1 wherein at least two laticesselected from the butadiene polymer latices (A), (B) and (C), areproduced by seed polymerisation.
 5. Polymer composition according toclaim 4, wherein all three butadiene polymer latices (A), (B) and (C),are produced by seed polymerisation.
 6. Polymer compositions accordingto claim 1 containing in addition at least one resin selected from thegroup consisting of an aromatic polycarbonate, aromatic polyestercarbonate, polyester and polyamide.
 7. Polymer compositions according toclaim 1 characterised in that in the production of the graft rubberpolymers the monomers are added in such a way that 55 to 90 wt. % of allthe monomers used in the graft polymerisation are metered in within thefirst half of the overall time for metering in the monomers, and theremaining proportion of the monomers is metered in within the secondhalf of the overall time for metering in the monomers.
 8. Polymercompositions according to claim 1 characterised in that in theproduction of the graft rubber polymers the temperature differencebetween the start and end of the grafting reaction is at least 15° C. 9.Process for producing polymer compositions according to claim 1characterised in that the components I) and II) are mixed and are thencompounded and extruded at elevated temperature.
 10. A molded articlecomprising the polymer composition of claim
 1. 11. Process for producinga polymer composition, wherein a graft rubber polymer that is obtainedby emulsion polymerisation of styrene and acrylonitrile in a weightratio of 95:5 to 50:50, wherein styrene and/or acrylonitrile can bewholly or partially replaced by a-methylstyrene, methyl methacrylate orN-phenylmaleimide or mixtures thereof, is produced in the presence of amixture of a butadiene polymer latex (A) with a mean particle diameterd₅₀≦250 nm and a particle size distribution width (measured as d₉₀–d₁₀from the integral particle size distribution) of 20 to 80 nm and a gelcontent of 30 to 95 wt. %, a butadiene polymer latex (B) with a meanparticle diameter d₅₀≦250 to 350 nm, a particle size distribution width(measured as d₉₀–d₁₀ from the integral particle size distribution) of 30to 100 nm, and a gel content of 30 to 80 wt. %, and a butadiene polymerlatex (C) with a mean particle diameter d₅₀>350 nm, a particle sizedistribution width (measured as d₉₀–d₁₀ from the integral particle sizedistribution) of 40 to 150 nm, and a gel content of 50 to 95 wt. %,using at least one latex produced by seed polymerisation and selectedfrom the butadiene polymer latices (A),(B) and (C), wherein thebutadiene polymer latices in each case contain 0 to 50 wt. % of afurther vinyl monomer incomorated by copolymerisation and wherein theweight ratio of graft polymers that are used to the butadiene polymersthat are used is 5:95 to 70:30, and the graft polymer is mixed with atleast one rubber-free copolymer of styrene and acrylonitnie in a weightratio of 95:5 to 50:50, wherein styrene and/or acrylonitrile may bepartially or wholly replaced by alpha-styrene, methyl methacrylate orN-phenylmaleimide or mixtures thereof.
 12. Graft rubber polymer that isobtained by emulsion polyrnerisation of styrene and acrylonttrile in aweight ratio of 95:5 to 50:50, wherein styrene and/or acrylonitrile canbe wholly or partially replaced by α-methyistyrene, methyl methacrylateor N-phenylmaleimide or mixtures thereof, in the presence of a mixtureof a butadiene polymer latex (A) with a mean particle diameter d₅₀≦250nm and a particle size distribution width (measured as d₉₀–d₁₀ from theintegral particle size distribution) of 20 to 80 nm, and a gel contentof 30 to 95 wt. %, a butadiene polymer latex (B) with a mean particlediameter d₅₀>250 to 350 nm, a particle size distribution width (measuredas d₉₀–d₁₀ from the integral particle size distribution) of 30 to 100nm, and a gel content of 30 to 80 wt. %, and a butadiene polymer latex(C) with a mean particle diameter d₅₀>350 nm, a particle sizedistribution width (measured as d₉₀–d₁₀ from the integral particle sizedistribution) of 40 to 150 nm, and a gel content of 50 to 95 wt. %,wherein the butadiene polymer lafices in each case contain 0 to 50 wt. %of a further vinyl monomer incorporated by copolymerisation, wherein theweight ratio of the graft monomers that are used to the butadienepolymers latices that are used is 5:95 to 70:30, and wherein at leastone latex selected from the butadiene polymer latices (A), (B) and (C)is produced by seed polymerisation.